# Python 2.6.4
# Project Euler, Problem 20
# Copyright 2010 Talha Zaman

def fac(n): return reduce(lambda x,y:x*y, range(1, n+1),1)
k = str(fac(100))
sum=0
for i in range(0, len(k)):
    sum += int(k[i])
print sum

